Radio Frequency Identification (RFID)
RFID refers to methods for automatic identification of objects via radio. The use of RFID systems is suitable basically wherever tagging, identifying, registering, storing, monitoring or transport is necessary.
RFID systems come in multiple variations. Despite the wide range of RFID solutions every RFID system is defined by the following three characteristics:
- electronic identification:
The system allows a unique identification of objects by electronically stored data.
- contactless data transfer:
The data used to identify the object is read wirelessly over a radio frequency channel.
- "on call" sending:
A marked object sends its data only if a designated reader asks for this process.
From a technological point of view, an RFID system consists of two components, a transponder and a reader:
- The transponder - also called "tag" - acts as a data storage holder. It is attached to an object (for example, a product or packaging) or integrated into an object (e.g. in a chip card) and can be read out without contact by means of radio technology and, depending on the technology used, can also be written on. Basically, the transponder consists of an integrated circuit and a radio frequency module. Stored on the transponder itself is an identification number and other data about the transponder or the object associated with it.
- The acquisition device - typically known and hereafter referred to only as a reader – consists of a read or respectively a write unit and an antenna - depending on the technology used. The reader reads data from the transponder and instructs the transponder to store further data. Furthermore, the reader controls the quality of data transmission. The readers are typically equipped with an additional interface to forward the received data to another system (PC, automatic control, ...) for further processing.
RFID systems use different frequency ranges from long wave to the microwave range. Another distinguishing feature of RFID systems is the storage technology used. This distinction is made between read-only and read-write systems.
The type of energy supply of the transponder and the resulting distinction between active transponders with their own power source or passive transponders, that are supplied with energy by the reader, is of fundamental importance. Because of these characteristics, groups of RFID systems can be formed and distinguished by the performance of their respective components in low-end systems, systems of medium performance and high-end systems.
RFID systems can also be grouped according to their respective ranges - that is, the maximum possible distance between transponder and reader.
Usually close-coupling, remote coupling and long-range systems are distinguished.
The design of transponders ranges from glass-injection fluid via the electronic ear mark to credit card formats, different slice designs as well as impact-resistant and heat-resistant (up to 200° Celsius) storage media for the paint lines of the automotive industry. The flexible lay-out of the identification points, size, shape and field pattern of the antenna make RFID systems an extremely versatile automatic identification technology. These groupings provide both a classification of RFID systems based on potential applications and provide an evaluation of the related issues concerning information security and data protection.